The present invention relates to an ink jet recording device for, using jetted ink particles, printing letters or characters or drawing patterns on an object to be printed, which is conveyed in a production line.
According to such an ink jet recording technology, it is possible to reduce volatilization of solvent components from the ink by supplying exhaust gas to a printing head and circulating the same. However, in an ink jet recording device, since solvents used during nozzle washing when operation of the device is stopped and the other maintenances enter an ink circulation path, ink concentration will be reduced.
For this reason, when discharging of the exhaust gas outside the device is continued, solvent components volatilized from ink will also be discharged outside the device, and therefore, the ink concentration will gradually return to around the original concentration thereof.
On the other hand, if the technology of circulating the exhaust gas is continuously used, volatilized amount of solvent components from the ink becomes small since circulating exhaust gas is saturated with solvent vapor, so that there is a problem that control of the ink concentration within a desired concentration range will be difficult, disabling a stable and good printing result to be obtained.
Moreover, in the above-mentioned ink jet recording device, positions and manners to connect a pipe which guides solvent vapor exhausted from an ink container to a gutter with the gutter are not considered. Moreover, the flow path shape of the gutter and the shape of ink collision plane are also not considered.
For this reason, although the gutter has a function to receive ink particles not used for printing, and by sucking them using negative pressure to recover them into an ink container, there has been a problem that, at some connection positions between the ink flow path of the gutter and the solvent vapor exhausted from the ink container, the suction force for the ink may reduce, and the ink once entered the gutter may back-flow and overflow, resulting in pollution of environment of the device.
Moreover, there has also been a problem that if the ink collides vertically to an ink collision plane in the gutter, scattered ink droplets occur during collision, and in some cases, they may fly out from the gutter and collide with ink particles for printing, resulting in disturbance of printing.
Further, there has also been a problem that if the connection between a path connected to the ink container and the gutter is imperfect, the solvent vapor is flown out from the imperfection part, and air is taken in from external air.
Moreover, a device in which a single device has two jet nozzles is known. However, a technology to provide a flow path for supplying gas taken in during recovering ink into the gutter with the device having two jet nozzles has not been proposed.
Therefore, in an ink jet recording device which has two or more nozzles, the volatilized matters of the solvent components contained in ink have been discharged outside the device.
When a single device has two nozzles for continuously spouting ink, two gutters for collecting ink not used for recording are also needed. Although, it is also possible to, while matching the two jet directions with the collection port of one gutter, collect ink simultaneously by one gutter, in order to detect the minute amount of electrifications for checking the electrification timing of ink particles after they are collected by the gutter, it is desirable to have two gutters.
During recovering the ink after collected in the ink container, since both of the two gutters have taken gas in, the solvent components of the ink is volatilized in the gas during recovering, and the gas returns to the ink container while containing the solvent vapor. Although, a prior art technology where the solvent vapor is supplied from the ink container via a solvent vapor supply flow path to the gutters, is known, if the solvent vapor is supplied to only anyone of the two gutters, for example a gutter A, a gutter B to which the solvent vapor is not supplied, will newly take external air in.
This leads to collapse of the balance between the recovery amount and the supply amount of the gas, thereby, disables the gutter A to circulate at 100%, causing a part of the solvent vapor supplied to the gutter A to be discharged outside the device from the collection port of gutter A. Moreover, if the gas circulates only through the gutter A, there is possibility that the gutter B to which the gas is not supplied cannot take in gas, and due to poor suction force for ink, the ink collected by the gutter B overflows from the collection port of the gutter.